| author |  scurest <scurest@users.noreply.github.com> 2017-10-23 15:40:49-05:00 |
| committer | scurest <scurest@users.noreply.github.com> 2017-10-23 15:40:49-05:00 |
| log | 03a0dfbeca4b31d235097c66c9891d825cf73c15 |
| tree | 627ee5acfe6c8ba382e9b53b282d31444a7ed639 |
| parent | c1642355f0b05f182c0b6d81d294d12be79ad0a8 |
Print better floats
2 files changed, 33 insertions(+), 17 deletions(-)
std/fmt/errol/index.zig+6-6
| ... | ... | @@ -38,7 +38,7 @@ fn errol3u(val: f64, buffer: []u8) -> FloatDecimal { |
| 38 | 38 | return errolFixed(val, buffer); |
| 39 | 39 | } |
| 40 | 40 | |
| 41 | ||
| 41 | ||
| 42 | 42 | // normalize the midpoint |
| 43 | 43 | |
| 44 | 44 | const e = math.frexp(val).exponent; |
| ... | ... | @@ -138,7 +138,7 @@ fn tableLowerBound(k: u64) -> usize { |
| 138 | 138 | |
| 139 | 139 | while (j < enum3.len) { |
| 140 | 140 | if (enum3[j] < k) { |
| 141 | j = 2 * k + 2; | |
| 141 | j = 2 * j + 2; | |
| 142 | 142 | } else { |
| 143 | 143 | i = j; |
| 144 | 144 | j = 2 * j + 1; |
| ... | ... | @@ -217,7 +217,7 @@ fn hpMul10(hp: &HP) { |
| 217 | 217 | |
| 218 | 218 | hp.val *= 10.0; |
| 219 | 219 | hp.off *= 10.0; |
| 220 | ||
| 220 | ||
| 221 | 221 | var off = hp.val; |
| 222 | 222 | off -= val * 8.0; |
| 223 | 223 | off -= val * 2.0; |
| ... | ... | @@ -241,7 +241,7 @@ fn errolInt(val: f64, buffer: []u8) -> FloatDecimal { |
| 241 | 241 | var low: u128 = mid - fpeint((fpnext(val) - val) / 2.0); |
| 242 | 242 | var high: u128 = mid + fpeint((val - fpprev(val)) / 2.0); |
| 243 | 243 | |
| 244 | if (@bitCast(u64, val) & 0x1 != 0) { | |
| 244 | if (@bitCast(u64, val) & 0x1 != 0) { | |
| 245 | 245 | high -= 1; |
| 246 | 246 | } else { |
| 247 | 247 | low -= 1; |
| ... | ... | @@ -347,11 +347,11 @@ fn errolFixed(val: f64, buffer: []u8) -> FloatDecimal { |
| 347 | 347 | } |
| 348 | 348 | |
| 349 | 349 | fn fpnext(val: f64) -> f64 { |
| 350 | return @bitCast(f64, @bitCast(u64, val) + 1); | |
| 350 | return @bitCast(f64, @bitCast(u64, val) +% 1); | |
| 351 | 351 | } |
| 352 | 352 | |
| 353 | 353 | fn fpprev(val: f64) -> f64 { |
| 354 | return @bitCast(f64, @bitCast(u64, val) - 1); | |
| 354 | return @bitCast(f64, @bitCast(u64, val) -% 1); | |
| 355 | 355 | } |
| 356 | 356 | |
| 357 | 357 | pub const c_digits_lut = []u8 { |
std/fmt/index.zig+27-11
| ... | ... | @@ -244,30 +244,46 @@ pub fn formatBuf(buf: []const u8, width: usize, |
| 244 | 244 | } |
| 245 | 245 | |
| 246 | 246 | pub fn formatFloat(value: var, context: var, output: fn(@typeOf(context), []const u8)->bool) -> bool { |
| 247 | var buffer: [20]u8 = undefined; | |
| 248 | const float_decimal = errol3(f64(value), buffer[0..]); | |
| 249 | if (float_decimal.exp != 0) { | |
| 250 | if (!output(context, float_decimal.digits[0..1])) | |
| 251 | return false; | |
| 252 | } else { | |
| 253 | if (!output(context, "0")) | |
| 247 | var x = f64(value); | |
| 248 | ||
| 249 | // Errol doesn't handle these special cases. | |
| 250 | if (math.isNan(x)) { | |
| 251 | return output(context, "NaN"); | |
| 252 | } | |
| 253 | if (math.isPositiveInf(x)) { | |
| 254 | return output(context, "Infinity"); | |
| 255 | } | |
| 256 | if (math.isNegativeInf(x)) { | |
| 257 | return output(context, "-Infinity"); | |
| 258 | } | |
| 259 | if (x == 0.0) { | |
| 260 | return output(context, "0.0"); | |
| 261 | } | |
| 262 | if (x < 0.0) { | |
| 263 | if (!output(context, "-")) | |
| 254 | 264 | return false; |
| 265 | x = -x; | |
| 255 | 266 | } |
| 267 | ||
| 268 | var buffer: [32]u8 = undefined; | |
| 269 | const float_decimal = errol3(x, buffer[0..]); | |
| 270 | if (!output(context, float_decimal.digits[0..1])) | |
| 271 | return false; | |
| 256 | 272 | if (!output(context, ".")) |
| 257 | 273 | return false; |
| 258 | 274 | if (float_decimal.digits.len > 1) { |
| 259 | const start = if (float_decimal.exp == 0) usize(0) else usize(1); | |
| 260 | if (!output(context, float_decimal.digits[start .. math.min(usize(7), float_decimal.digits.len)])) | |
| 275 | const num_digits = if (@typeOf(value) == f32) { usize(8) } else { usize(17) }; | |
| 276 | if (!output(context, float_decimal.digits[1 .. math.min(num_digits, float_decimal.digits.len)])) | |
| 261 | 277 | return false; |
| 262 | 278 | } else { |
| 263 | 279 | if (!output(context, "0")) |
| 264 | 280 | return false; |
| 265 | 281 | } |
| 266 | 282 | |
| 267 | if (float_decimal.exp != 1 and float_decimal.exp != 0) { | |
| 283 | if (float_decimal.exp != 1) { | |
| 268 | 284 | if (!output(context, "e")) |
| 269 | 285 | return false; |
| 270 | if (!formatInt(float_decimal.exp, 10, false, 0, context, output)) | |
| 286 | if (!formatInt(float_decimal.exp - 1, 10, false, 0, context, output)) | |
| 271 | 287 | return false; |
| 272 | 288 | } |
| 273 | 289 | return true; |